As I am Remodeling my old house now a days and take advices from time to time on telephone or internet as i have no time left to go and find appropriate people and experts.
I am facing a problem with Water Tank on the roof. which is the storage of water supply to whole house. Problem is that when ever it overflow and water came out of it flows all over the roof. slope level of roof is very good. but i am seeing that damp is appearing on my ceilings near that place of Water Tank. I want advice whether i should resolve this problem from inside or outside and how.

No pictures?
I can not see how having a water tank sitting on a roof could ever be a good thing.
Water weighs over 7 lb. per gal. so between the weight and the fact that tank would have to be attached some how putting holes in the roof not a great plan.

Here in our country almost all water supply is based on individual Ground Boring. From where water is lifted up by an electrical water pump and is stored in a water Tank placed on the roof of house. Please see the pictures.

Your first photo shows a membrane and the second roof has none that can be seen. Hopefully someone will be familier with your roof and make some better suggestions. If that kind of roof is standard where you are, you may have to find local solutions.
Sorry I can't be more helpful.

Biggest problem I see is that the water tank is sitting on bricks. A gallon of water weighs 8.35 lbs and all the weight is sitting on the sharp edges of the bricks. If it was my tank I would empty it, pick up the tank, repair the holes punched into the roof membrane and then put the tank on a solid surface of what ever material you have available that won't decay. Make the base bigger to distribute the weight in a larger area. Bricks were a bad idea. Thats a lot of weight sitting on the bricks. How many gallon tank is it?

Suggestion is very attractive. The capacity of the tank is 200 Gallons. I would like to add one more thing. If i give a slope to the plat form on which i will place the tank after repair and connect it with a separate drain other than the roof slope then water will not stay there on whole roof.

Quote:

Originally Posted by oldog/newtrick

Biggest problem I see is that the water tank is sitting on bricks. A gallon of water weighs 8.35 lbs and all the weight is sitting on the sharp edges of the bricks. If it was my tank I would empty it, pick up the tank, repair the holes punched into the roof membrane and then put the tank on a solid surface of what ever material you have available that won't decay. Make the base bigger to distribute the weight in a larger area. Bricks were a bad idea. Thats a lot of weight sitting on the bricks. How many gallon tank is it?